GitLab

Network histograms audit

This CL:
* Marks some unused histograms as obsolete
* Updates ownership of some histograms
* Updates a few expires_after dates for consistency

BUG=1097831
R=chromium-metrics-reviews@google.com

Change-Id: Ice2d51014bd4211a0a70c0dd893c33c508cd5c02
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2568597Reviewed-by: Steven Holte <holte@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Commit-Queue: Steven Bennetts <stevenjb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#833442}